Stroke School for Internists – Part 1 November 4, 2017 Dr. Albert Jin Dr. Gurpreet Jaswal Disclosures • I receive a stipend for my role as Medical Director of the Stroke Network of SEO • I have no commercial disclosures or conflicts of interest Three Main Objectives • 1. Obtain a history and examination in five minutes in the ED • 2. Identify the stroke syndrome • 3. Read a plain noncontrast CT scan of the head and recognize thrombus, infarction, hemorrhage 1. Stroke History and Exam • The history (~ 3minutes) is focused on enabling a thrombolysis decision • The exam (~ 2 minutes) has two main aims: – Confirm the clinical suspicion of stroke – Clarify the stroke syndrome and localization • Within 5 minutes there is usually enough information to diagnose stroke • This sets up imaging as the decision point for thrombolysis “Last known well” • Last seen normal, or last known well is the time of onset – Time of onset is not necessarily when the patient was found – Time of onset is not necessarily when there was an abrupt change if the patient changed from having a mild deficit to a severe deficit – “When was the last time today that Mr. Jones was seen to be walking and talking normally?” What are the symptoms? • Weakness in face, arm or leg • Speech: Is it aphasia, or something else? • Sensory and Vision: Do they notice bilateral stimulation? • Ataxia: “Felt dizzy”, “Had to hold on to wall” Chronology • How quickly did symptoms reach maximal severity? – Symptom onset is often described as sudden – But symptoms often worsen after “sudden onset” – “Sudden onset right face and arm numbness” becomes “Sudden onset right face numbness which got worse over the next 30 minutes and spread to the right arm” • “Did things get worse after you first noticed problems? How long did it take to get to the very worst?” Medications, Comorbidities, Independence • Anticoagulants and when taken? Other meds? Allergies? • Medical conditions, recent stroke/TIA, recent trauma or surgery? • Are they independent at baseline? – If not independent, can they walk, converse, cognitive impairment? Examination in 3 minutes • NIH Stroke Scale • Consciousness • Gaze, Visual Fields, Start at head Face • Arm & leg: weak, Move to arms clumsy, numb and legs • Language Back up to the • Dysarthria head • Inattention Let’s practice the NIHSS • Please pair off and we’ll go through the examination technique together NIHSS 2. Stroke Syndromes Objectives • Recognize clinical features of anterior circulation stroke involving: • Middle cerebral artery • Anterior cerebral artery • Recognize features of posterior circulation stroke involving: • Posterior cerebral artery (occipital lobe, thalamus, medial temporal lobe) • Brainstem (midbrain, pons, medulla) • Cerebellum • Recognize four common lacunar stroke syndromes • Pure motor stroke • Pure sensory stroke • Sensorimotor stroke • Ataxic hemiparesis • Clumsy hand-dysarthria Anterior Circulation Stroke • MCA and/or ACA • Occlusion of the ICA can result in ischemia in both MCA and ACA territory simultaneously Middle cerebral artery • About two-thirds of all ischemic stroke occurs in the middle cerebral artery territory • MCA stroke can involve the frontal, temporal, and parietal lobes • MCA stroke can also involve the basal ganglia through the lenticulostriate arteries • The MCA covers a large territory shown in blue on this CT scan image taken at the basal ganglionic level MCA covers a large portion of the hemisphere MCA stroke syndromes • Left hemisphere • Right hemisphere (ie, dominant) (ie, nondominant) • Left hemiparesis • Right hemiparesis • Left-sided sensory • Right-sided sensory loss loss • Left homonymous • Right homonymous hemianopia hemianopia • Dysarthria • Neglect of the left • Dysarthria side of • Aphasia environment Anterior cerebral artery ACA covers the medial portion of the brain ACA stroke syndrome • Contralateral leg paresis > arm paresis • Or, bilateral leg weakness if both ACAs are involved • Abulia, disinhibition, executive dysfunction • In some cases, akinetic mutism if bilateral caudate head infarction Posterior Circulation • This includes: – Vertebral arteries – Posterior and anterior inferior cerebellar posterior artery inferior – Basilar artery cerebellar artery Left PCA infarction on CT Medial temporal lobe infarct Medial occipital lobe infarct This is a thrombus in the left PCA PCA stroke syndromes • The most common syndromes involve the occipital lobe, the medial temporal lobe or the thalamus • Occipital lobe: – Contralateral homonymous hemianopia – Cortical blindness (bilateral lesions) • Medial temporal lobe: – Deficits in long-term and short-term memory – Behaviour alteration (agitation, anger, paranoia) PCA stroke syndromes, cont’d • Thalamic infarct – Contralateral sensory loss – Aphasia (if dominant side involvement) – Executive dysfunction – Decreased level of consciousness – Memory impairment Brainstem stroke syndromes • Some of the clinical features seen are: – Crossed sensory findings (e.g. ipsilateral face and contralateral body numbness) – Crossed motor findings (ipsilateral face, contralateral body) – Gaze-evoked nystagmus Other findings in brainstem stroke – Ataxia and vertigo, limb dysmetria – Diplopia and eye movement abnormalities – Dysarthria, dysphagia – Tongue deviation – Deafness (very rare) – Locked-in syndrome (can’t move any limb, can’t speak, can sometimes blink Midbrain stroke • Ipsilateral 3rd nerve palsy • Contralateral hemiparesis of the arm and leg, sometimes with hemiplegia of the face • Contralateral hemiataxia Pontine stroke • Ipsilateral signs: – Horner’s syndrome – 6th or 7th nerve palsy (diplopia, whole side of face is weak) – Hearing loss (rare) – Loss of pain and temperature sense • Contralateral signs: – Weakness in leg and arm – Loss of sensation in arm and leg • Nystagmus, nausea Medullary stroke • Ipsilateral signs: • Tongue weakness • Sensory loss in face • Horner’s syndrome • Ataxia • Palate weakness (dysphagia) • Contralateral signs: • Weakness, sensory loss in arm and leg • Nausea, nystagmus, Medullary infarct on dysphagia, dysarthria diffusion-weighted imaging Cerebellar stroke • Ataxia, vertigo, nausea, vomiting, dysarthria • Often headache and nystagmus • Can also have rapid deterioration in level of consciousness Cerebellar infarction • Infarction causes edema resulting in mass effect, herniation and compression of the fourth ventricle • This can lead to rapid deterioration in level of consciousness • Surgical decompression is often necessary in these circumstances Lacunar stroke syndromes • Pure motor stroke • Pure sensory stroke usually arises from usually arises from infarction in the posterior thalamic infarction limb of the internal capsule; course is often stuttering over hours to days: Lacunar stroke syndromes • Sensorimotor stroke can arise from infarcts at the junction between the thalamus and the internal capsule • As the name implies, the symptoms consist of weakness and sensory loss with no visual field deficit, aphasia, neglect or other symptoms Lacunar stroke syndromes • Ataxic hemiparesis often arises from infarction in the corona radiata • Ataxia is unilateral and is in excess of the mild weakness found on exam Lacunar stroke syndromes • Clumsy hand-dysarthria is caused by infarction in the pons, but can also occur in corona radiata and the internal capsule • Contralateral facial weakness with dysarthria and dysphagia occurs with contralateral hand weakness/ataxia, and sometimes weakness in the arm or leg Summary • MCA stroke: hemiparesis, sensory loss, hemianopia, and either aphasia or neglect • ACA stroke: leg weakness and executive dysfunction • PCA stroke: hemianopia, pure sensory infarct (thalamus), memory impairment, decreased level of consciousness • Brainstem strokes: crossed sensory or motor findings, nystagmus, ataxia, dysarthria, diplopia, vertigo, Horner’s syndrome • Cerebellar strokes: ataxia, nystagmus, vertigo, nausea, headache and rapid deterioration in consciousness • Lacunar strokes: pure motor, pure sensory, sensorimotor, ataxic hemiparesis, clumsy hand-dysarthria 3. How to read a CT scan We will learn the following: • Recognize basic anatomical structures on a plain CT head • Recognize acute thrombus in the MCA • Recognize acute ischemic stroke • Recognize acute intracranial hemorrhage Reading a plain CT head • Know the following levels on an axial CT: – Medulla, Cerebellum, and Vertebral Arteries – Pons, and Basilar Artery – Midbrain, and Proximal Middle Cerebral Arteries – Basal ganglia and Insula – Corona radiata – Centrum semiovale Reading a plain CT head Medulla • It helps to know where you are in the brain when scrolling through a plain CT head: – Medulla and Cerebellum – Pons – Midbrain – Basal ganglia – Corona radiata Left – Centrum semiovale vertebral Cerebellum artery Pons Basilar artery Midbrain Middle cerebral artery Basal ganglia: Caudate and Lentiform Nuclei Insula Thalamus Corona radiata Centrum semiovale Central sulcus Recognize acute thrombus • As you review the following slides, recall that the Midbrain level is where you see the proximal MCA (and distal ICA) Detecting early cerebral ischemia on CT scan • Loss of grey-white differentiation – You may have to adjust the brightness and contrast (the “window width” and “window level”) • Loss of sulci • Use the same system every time you look at a CT for possible acute stroke – For example, the Alberta Stroke Program Early CT Score (ASPECTS) Alberta Stroke Program Early CT Score M1 M4 C I L M2 M5 IC M3 M6 C = caudate, L = lentiform, I = insula, IC = internal capsule M1, M2, M3 = anterior, lateral, posterior MCA territory; M4 to M6 are above the lentiform nuclei Right hemiparesis and aphasia: Where is the infarct? Can you see the infarct using ASPECTS? I M2 M5 Case • 77 year old female with left hemiparesis, left homonymous hemianopia, left side sensory loss Intracranial Hemorrhage • http://radiopaedia.org/articles/intracranial- haemorrhage Subarachnoid hemorrhage, acute Lobar hemorrhage, acute Intraventricular hemorrhage, acute Epidural hemorrhage, acute Subdural hematoma, acute Subdural hematoma, chronic Subdural hemorrhage, acute on chronic End of Part 1 of Stroke School.